Page 31 - DCAP308_OBJECT_ORIENTED_ANALYSIS_AND_DESIGN

Anil Sharma, Lovely Professional University
Unit 3: Class Modelling

Unit 3: Class Modelling Notes

CONTENTS
Objectives

Introduction
3.1 Object and Class Concepts
3.1.1 Class

3.1.2 Objects
3.2 Link and Association Concepts
3.2.1 General Concepts
3.2.2 Multiplicity

3.3 Generalization and Inheritance
3.3.1 Generalization

3.3.2 Inheritance
3.4 Sample Class Model
3.4.1 Navigation of Class Model
3.5 Summary

3.6 Keywords
3.7 Review Questions
3.8 Further Readings

Objectives

After studying this unit, you will be able to:
Discuss object and class concepts
Explain link and association concepts

Discuss generalization and inheritance
Explain sample class model

Introduction

In this unit, we will discuss various characteristics of class modeling. Before we discuss the
characteristics of object oriented modeling, let us see how object oriented development is different
from structured development of the system. In the structured approach, the main emphasis is on
specifying and decomposing system functionality. Structured approach is seen as the most
direct way of implementing a desired goal. A structured approach has certain basic problems,
such as, if the requirements of system change then a system based on decomposing functionality
may require massive restructuring, and, the system gradually become unmanageable. In contrast
to the structured approach, the basic focus of object-oriented approach is to identify objects from
the application domain, and then to associate procedures (methods) around these identified

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